In laparoscopic surgical procedures, a small incision is made in the body. A trocar is inserted through the incision. The trocar receives an elongate shaft of a surgical device to position a distal end of the shaft at a surgical worksite. In some endoscopic procedures, the elongate shaft of the surgical device is inserted through a natural orifice of the patient, such as the mouth, vagina, or anus, and is advanced along an internal pathway to position the distal end of the device at the surgical worksite. Endoscopic procedures typically require the use of a flexible shaft to accommodate the tortuous pathway of the body lumen, whereas rigid shafts can be used in laparoscopic procedures. These tools can be used to engage and/or treat tissue in a number of ways to achieve a diagnostic or therapeutic effect.
Endoscopic surgery can be used to access the abdominal cavity via natural openings (mouth, anus, vagina, urethra) of the body and through the peritoneal lining of the abdominal cavity. The size and shape of instruments that may be passed through a body lumen to perform a medical procedure in the abdominal cavity are greatly restricted due to the anatomical properties of the lumen. General surgeons, gastroenterologists, and other medical specialists, routinely use flexible endoscopes for intralumenal (within the lumen of the alimentary canal) examination and treatment of the upper gastrointestinal (GI) tract, via the mouth, and the lower GI tract, via the anus. In these procedures, the physician pushes the flexible endoscopes into the lumen, periodically pausing to articulate the distal end of the endoscope. In this manner, the physician may navigate the crooked passageway of the upper GI past the pharynx, through the esophagus and gastroesophageal junction, and into the stomach. In the process, the physician must take great care not to injure the delicate mucosal lining of the lumen, which has a non-circular cross sectional configuration when relaxed, but can stretch open to a diameter in the range of about 15-25 mm during the insertion procedure.
During translumenal procedures, a puncture must be formed in the stomach wall, gastrointestinal tract, or other epithelialized natural orifice to access the peritoneal cavity. A needle knife is one device often used to form such a puncture. The needle knife is inserted through the working channel of the endoscope and utilizes energy to penetrate through the tissue. A guidewire is then feed through the endoscope and is passed through the puncture in the stomach wall and into the peritoneal cavity. When the needle knife is removed, the guidewire is left as a placeholder. A balloon catheter is then passed over the guidewire through the working channel of the endoscope to position the balloon within the opening in the stomach wall. The balloon is inflated to increase the size of the opening, thereby enabling the endoscope to push against the rear of the balloon and to be feed through the dilated opening and into the peritoneal cavity. Once the endoscope is positioned within the peritoneal cavity, numerous procedures can be performed with instruments introduced through the one or more working channels of the endoscope.
While current methods and devices used to articulate and steer flexible endoscopes into a natural orifice of a patient are effective, there are no articulatable steerable flexible cannulas or trocars that are sufficiently flexible for receiving an endoscope while simultaneously having sufficient column strength for inserting into internal body lumens or cavities. Traditional overtubes that slide over the endoscope generally are not sufficiently flexible, articulatable or steerable, and do not have sufficient column strength to be inserted into internal body lumens or cavities, such as the peritoneal cavity.
Accordingly, there remains a need for improved endoscopic translumenal methods and devices.